SAB-C509-LM SIEMENS [Siemens Semiconductor Group], SAB-C509-LM Datasheet - Page 41

• Manufacturer Part Number: SAB-C509-LM
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Timer / Counter 0 and 1
Timer/Counter 0 and 1 can be used in four operating modes as listed in table 6 :
Table 6
Timer/Counter 0 and 1 Operating Modes
Mode
0
1
2
3
In the “timer” function (C/T = ‘0’) the register is incremented by a count rate of
In the “counter” function the register is incremented in response to a 1-to-0 transition at its
corresponding external input pin (P3.4/T0, P3.5/T1). Since it takes two machine cycles to detect a
falling edge the max. count rate is
programmed to function as a gate to facilitate pulse width measurements. Figure 17 illustrates the
input clock logic of timer 0/1.
Figure 17
Timer/Counter 0 and 1 Input Clock Logic
Semiconductor Group
Description
8-bit timer/counter with a
divide-by-32 prescaler
16-bit timer/counter
8-bit timer/counter with
8-bit autoreload
Timer/counter 0 used as one
8-bit timer/counter and one
8-bit timer
Timer 1 stops
f
OSC
/12. External inputs INT0 and INT1 (P3.2, P3.3) can be
M1
0
0
1
1
TMOD
40
M0
0
0
1
1
f
f
OSC
OSC
f
OSC
/6 up to
internal
/6x32 up to
/48x32
48
TxP1
0
0
1
1
f
OSC
Input Clock
/
TxP0
0
1
0
1
f
external (max)
OSC
f
OSC
/6 up to
f
Prescaler
6
12
24
48
OSC
/12x32
/12
C509-L
f
OSC
/32.